Dial system for a steering wheel of an automobile

1. A dial system for a steering wheel of an automobile comprising a first dial, a second dial respectively mounted on two opposite sides of the steering wheel and a controller disposed on the automobile for receiving and processing signals from the first dial and the second dial, wherein: each of the first dial and the second dial comprises: a first housing including a longitudinal opening, a plurality of stubs, and a stopper having a plurality of bores; a dial set received in the first housing and including a metal plate mounted to the first housing, and a plurality of number buttons secured on the metal plate and received in the longitudinal opening in the first housing; a circuit board received in the first housing, the circuit board including a plurality of button switches electrically mounted thereon, each button switch aligning with a corresponding one of the longitudinal number buttons such that the button switch is operated when the corresponding number button is pressed, and a radio frequency (RF) transmitter electrically disposed on the circuit board for wirelessly transmitting the signals to the controller; a second housing mounted to the first housing to form a space for receiving the dial set and the circuit board; a battery seat with a battery laterally inserted into a space between the first housing and the second housing, the battery electrically connected to the circuit board for supplying power to the circuit board when the battery seat is inserted into the space between the first housing and the second housing; and a clamp mounted to the bottom of the second housing and adapted to clamp the steering wheel to hold the dial system in place on the steering wheel; and the controller comprises: a circuit board with a bluetooth circuit mounted therein for transmitting the signals to a mobile phone having a bluetooth module; and a microphone and a speaker respectively disposed on the controller such that a driver can use the speaker and the microphone for conversation while driving without holding the mobile phone; and wherein the stubs extend through the metal plate and the bores of the stopper to hold the metal plate in place; and further comprising a cable interconnecting the first dial and the second dial such that the first dial and the second dial are adapted to share power and the RF transmitter.